import java.io.*;

/**
 * Base64 implements Base64 encoding and Base 64 decoding.
 *
 */
 
public class Base64 implements Serializable {
	private static byte[] Base64EncMap, Base64DecMap;
	static {
		// rfc-2045: Base64 Alphabet
		byte[] map = {(byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) '+', (byte) '/'};
		Base64EncMap = map;
		Base64DecMap = new byte[128];
		for (int idx = 0; idx < Base64EncMap.length; idx++)
			Base64DecMap[Base64EncMap[idx]] = (byte) idx;
	}
/**
 * constructor
 *
*/
public Base64 ()
{
}
	/**
	 * This method decodes the given byte[] using the base64-encoding
	 * specified in RFC-2045 (Section 6.8).
	 *
	 * @param  data the base64-encoded data.
	 * @return the decoded data.
	 */
	public final static byte[] base64Decode(byte[] data)
		{
		if (data == null)  return  null;

		int tail = data.length;
		while (data[tail-1] == '=')  tail--;

		byte dest[] = new byte[tail - data.length/4];

		// ascii printable to 0-63 conversion
		for (int idx = 0; idx <data.length; idx++)
			data[idx] = Base64DecMap[data[idx]];

		// 4-byte to 3-byte conversion
		int sidx, didx;
		for (sidx = 0, didx=0; didx < dest.length-2; sidx += 4, didx += 3)
			{
			dest[didx]   = (byte) ( ((data[sidx] << 2) & 255) |
							((data[sidx+1] >>> 4) & 003) );
			dest[didx+1] = (byte) ( ((data[sidx+1] << 4) & 255) |
							((data[sidx+2] >>> 2) & 017) );
			dest[didx+2] = (byte) ( ((data[sidx+2] << 6) & 255) |
							(data[sidx+3] & 077) );
			}
		if (didx < dest.length)
			dest[didx]   = (byte) ( ((data[sidx] << 2) & 255) |
									((data[sidx+1] >>> 4) & 003) );
		if (++didx < dest.length)
			dest[didx]   = (byte) ( ((data[sidx+1] << 4) & 255) |
									((data[sidx+2] >>> 2) & 017) );

		return dest;
		}
/**
 * This method decodes the given string using the base64-encoding
 * specified in RFC-2045 (Section 6.8).
 *
 * @param  str the base64-encoded string.
 * @return the decoded str.
 */
public final static String base64Decode(String str)
{
	if (str == null)
		return null;
	byte data[] = new byte[str.length()];
	
	data = str.getBytes();
	
	return new String(base64Decode(data));
}
	/**
	 * This method encodes the given byte[] using the base64-encoding
	 * specified in RFC-2045 (Section 6.8).
	 *
	 * @param  data the data
	 * @return the base64-encoded data
	 */
	public final static byte[] base64Encode(byte[] data)
		{
		if (data == null)  return  null;

		int sidx, didx;
		byte dest[] = new byte[((data.length+2)/3)*4];

		// 3-byte to 4-byte conversion + 0-63 to ascii printable conversion
		for (sidx=0, didx=0; sidx < data.length-2; sidx += 3)
			{
			dest[didx++] = Base64EncMap[(data[sidx] >>> 2) & 077];
			dest[didx++] = Base64EncMap[(data[sidx+1] >>> 4) & 017 |
							(data[sidx] << 4) & 077];
			dest[didx++] = Base64EncMap[(data[sidx+2] >>> 6) & 003 |
							(data[sidx+1] << 2) & 077];
			dest[didx++] = Base64EncMap[data[sidx+2] & 077];
			}
		if (sidx < data.length)
			{
			dest[didx++] = Base64EncMap[(data[sidx] >>> 2) & 077];
			if (sidx < data.length-1)
				{
				dest[didx++] = Base64EncMap[(data[sidx+1] >>> 4) & 017 |
								(data[sidx] << 4) & 077];
				dest[didx++] = Base64EncMap[(data[sidx+1] << 2) & 077];
				}
			else
				dest[didx++] = Base64EncMap[(data[sidx] << 4) & 077];
			}

		// add padding
		for ( ; didx < dest.length; didx++)
			dest[didx] = (byte) '=';

		return dest;
		}
/**
 * This method encodes the given string using the base64-encoding
 * specified in RFC-2045 (Section 6.8).
 *
 * @param  str the string
 * @return the base64-encoded str
 */
public final static String base64Encode(String str)
{
	if (str == null)
		return null;
	byte data[] = new byte[str.length()];

	data = str.getBytes();
	return new String(base64Encode(data));
}
public static void main(String[] args) 
{
	System.out.println("This is not an executable application and is for reference only. Please view source code for Base64 encoding and decoding.");
}
}
